Field
Embodiments of the present disclosure generally relate to the fabrication of semiconductor and other electronic devices and methods for generating and forming a film on a substrate. More particularly, the present disclosure relates to a fabrication process for forming multiple layers on a substrate including a chalcogenide film layer.
Description of the Related Art
Reliably producing submicron and smaller features is one of the key technologies for the next generation of very large scale integration (VLSI) and ultra large scale integration (ULSI) of semiconductor devices. However, as the miniaturization of circuit technology is desired, reduced dimensions of interconnects in VLSI and ULSI technology has placed additional demands on processing capabilities. The multilevel interconnects that lie at the center of this technology require precise processing of high aspect ratio features, such as vias and other interconnects. Reliable formation of these interconnects is essential to VLSI and ULSI success and to the continued effort to increase circuit density and the overall quality of individual substrates.
Additionally, as circuit densities increase for next generation devices, the widths of interconnects, such as vias, trenches, contacts, gate structures, and other features, as well as the dielectric materials therebetween, decrease in dimension. However, the thickness of the dielectric layers may remain substantially constant. As such, an increase in the aspect ratio of the features results.
Furthermore, in the fabrication of integrated circuits, deposition processes such as chemical vapor deposition (CVD), atomic layer deposition (ALD), or plasma enhanced chemical vapor deposition (PECVD) processes are used to deposit films of various materials upon semiconductor substrates. Further reductions in device dimensions will require precise control over different aspects of the deposition processes, such as gas distribution uniformity, the generation of reacting species using microwave plasma energy, concentration uniformity, and control of the amount of gases provided to the surface of the substrate for two-dimensional (2D) films having a thickness less than one nanometer. Thus, there is a continuing need for an improved process platform to further enhance the control over different aspects of these deposition processes. Additionally, there is a continuing need for high reacting neutral species generation by microwave energy sources at or during low temperature (<500° C.) film depositions in CVD processing chambers and/or ALD processing chambers. Microwave plasma generated radicals are neutral, and chalcogens thermally crake to high concentrations of reacting species, such as S2, S4, Se2, etc. at low temperatures, unlike conventional plasma energy sources, which generate ion species which create defective 2D material film.
Two-dimensional (2D) materials, such as graphene, are a class of materials with a layered structure which leads to strong anisotropy in their electrical, chemical, mechanical, and thermal properties. The 2D transition metal dichalcogenides, with general formula MX2, generally maintain versatile properties. To illustrate, mono-layer or few-layered transition metal dichalcogenides are direct-gap semiconductors whose band gap energy, as well as carrier type (n-type or p-type), vary depending on the transition metals, chalcogens, dopants, composition and structure of the 2D film. Thus, what are needed in the art are improved apparatus and methods for material deposition.